CVE-2024-56559

CVE-2024-56559 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-667.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: mm/vmalloc: combine all TLB flush operations of KASAN shadow virtual address into one operation When compiling kernel source 'make -j $(nproc)' with the up-and-running KASAN-enabled kernel on a 256-core machine, the following soft lockup is shown: watchdog: BUG: soft lockup - CPU#28 stuck for 22s! [kworker/28:1:1760] CPU: 28 PID: 1760 Comm: kworker/28:1 Kdump: loaded Not tainted 6.10.0-rc5 #95 Workqueue: events drain_vmap_area_work RIP: 0010:smp_call_function_many_cond+0x1d8/0xbb0 Code: 38 c8 7c 08 84 c9 0f 85 49 08 00 00 8b 45 08 a8 01 74 2e 48 89 f1 49 89 f7 48 c1 e9 03 41 83 e7 07 4c 01 e9 41 83 c7 03 f3 90 <0f> b6 01 41 38 c7 7c 08 84 c0 0f 85 d4 06 00 00 8b 45 08 a8 01 75 RSP: 0018:ffffc9000cb3fb60 EFLAGS: 00000202 RAX: 0000000000000011 RBX: ffff8883bc4469c0 RCX: ffffed10776e9949 RDX: 0000000000000002 RSI: ffff8883bb74ca48 RDI: ffffffff8434dc50 RBP: ffff8883bb74ca40 R08: ffff888103585dc0 R09: ffff8884533a1800 R10: 0000000000000004 R11: ffffffffffffffff R12: ffffed1077888d39 R13: dffffc0000000000 R14: ffffed1077888d38 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8883bc400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005577b5c8d158 CR3: 0000000004850000 CR4: 0000000000350ef0 Call Trace: <IRQ> ? watchdog_timer_fn+0x2cd/0x390 ? __pfx_watchdog_timer_fn+0x10/0x10 ? __hrtimer_run_queues+0x300/0x6d0 ? sched_clock_cpu+0x69/0x4e0 ? __pfx___hrtimer_run_queues+0x10/0x10 ? srso_return_thunk+0x5/0x5f ? ktime_get_update_offsets_now+0x7f/0x2a0 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? hrtimer_interrupt+0x2ca/0x760 ? __sysvec_apic_timer_interrupt+0x8c/0x2b0 ? sysvec_apic_timer_interrupt+0x6a/0x90 </IRQ> <TASK> ? asm_sysvec_apic_timer_interrupt+0x16/0x20 ? smp_call_function_many_cond+0x1d8/0xbb0 ? __pfx_do_kernel_range_flush+0x10/0x10 on_each_cpu_cond_mask+0x20/0x40 flush_tlb_kernel_range+0x19b/0x250 ? srso_return_thunk+0x5/0x5f ? kasan_release_vmalloc+0xa7/0xc0 purge_vmap_node+0x357/0x820 ? __pfx_purge_vmap_node+0x10/0x10 __purge_vmap_area_lazy+0x5b8/0xa10 drain_vmap_area_work+0x21/0x30 process_one_work+0x661/0x10b0 worker_thread+0x844/0x10e0 ? srso_return_thunk+0x5/0x5f ? __kthread_parkme+0x82/0x140 ? __pfx_worker_thread+0x10/0x10 kthread+0x2a5/0x370 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x30/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Debugging Analysis: 1. The following ftrace log shows that the lockup CPU spends too much time iterating vmap_nodes and flushing TLB when purging vm_area structures. (Some info is trimmed). kworker: funcgraph_entry: | drain_vmap_area_work() { kworker: funcgraph_entry: | mutex_lock() { kworker: funcgraph_entry: 1.092 us | __cond_resched(); kworker: funcgraph_exit: 3.306 us | } ... ... kworker: funcgraph_entry: | flush_tlb_kernel_range() { ... ... kworker: funcgraph_exit: # 7533.649 us | } ... ... kworker: funcgraph_entry: 2.344 us | mutex_unlock(); kworker: funcgraph_exit: $ 23871554 us | } The drain_vmap_area_work() spends over 23 seconds. There are 2805 flush_tlb_kernel_range() calls in the ftrace log. * One is called in __purge_vmap_area_lazy(). * Others are called by purge_vmap_node->kasan_release_vmalloc. purge_vmap_node() iteratively releases kasan vmalloc allocations and flushes TLB for each vmap_area. - [Rough calculation] Each flush_tlb_kernel_range() runs about 7.5ms. -- 2804 * 7.5ms = 21.03 seconds. -- That's why a soft lock is triggered. 2. Extending the soft lockup time can work around the issue (For example, # echo ---truncated---

Frequently asked questions

What is CVE-2024-56559?
In the Linux kernel, the following vulnerability has been resolved: mm/vmalloc: combine all TLB flush operations of KASAN shadow virtual address into one operation When compiling kernel source 'make -j $(nproc)' with the up-and-running KASAN-enabled kernel on a 256-core machine, the following soft lockup is shown: watchdog: BUG: soft lockup - CPU#28 stuck for 22s! [kworker/28:1:1760] CPU: 28 PID: 1760 Comm: kworker/28:1 Kdump: loaded Not tainted 6.10.0-rc5 #95 Workqueue: events drain_vmap_area_work RIP: 0010:smp_call_function_many_cond+0x1d8/0xbb0 Code: 38 c8 7c 08 84 c9 0f 85 49 08 00 00 8b 45 08 a8 01 74 2e 48 89 f1 49 89 f7 48 c1 e9 03 41 83 e7 07 4c 01 e9 41 83 c7 03 f3 90 <0f> b6 01 41 38 c7 7c 08 84 c0 0f 85 d4 06 00 00 8b 45 08 a8 01 75 RSP: 0018:ffffc9000cb3fb60 EFLAGS: 00000202 RAX: 0000000000000011 RBX: ffff8883bc4469c0 RCX: ffffed10776e9949 RDX: 0000000000000002 RSI: ffff8883bb74ca48 RDI: ffffffff8434dc50 RBP: ffff8883bb74ca40 R08: ffff888103585dc0 R09: ffff8884533a1800 R10: 0000000000000004 R11: ffffffffffffffff R12: ffffed1077888d39 R13: dffffc0000000000 R14: ffffed1077888d38 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8883bc400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005577b5c8d158 CR3: 0000000004850000 CR4: 0000000000350ef0 Call Trace: <IRQ> ? watchdog_timer_fn+0x2cd/0x390 ? __pfx_watchdog_timer_fn+0x10/0x10 ? __hrtimer_run_queues+0x300/0x6d0 ? sched_clock_cpu+0x69/0x4e0 ? __pfx___hrtimer_run_queues+0x10/0x10 ? srso_return_thunk+0x5/0x5f ? ktime_get_update_offsets_now+0x7f/0x2a0 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? hrtimer_interrupt+0x2ca/0x760 ? __sysvec_apic_timer_interrupt+0x8c/0x2b0 ? sysvec_apic_timer_interrupt+0x6a/0x90 </IRQ> <TASK> ? asm_sysvec_apic_timer_interrupt+0x16/0x20 ? smp_call_function_many_cond+0x1d8/0xbb0 ? __pfx_do_kernel_range_flush+0x10/0x10 on_each_cpu_cond_mask+0x20/0x40 flush_tlb_kernel_range+0x19b/0x250 ? srso_return_thunk+0x5/0x5f ? kasan_release_vmalloc+0xa7/0xc0 purge_vmap_node+0x357/0x820 ? __pfx_purge_vmap_node+0x10/0x10 __purge_vmap_area_lazy+0x5b8/0xa10 drain_vmap_area_work+0x21/0x30 process_one_work+0x661/0x10b0 worker_thread+0x844/0x10e0 ? srso_return_thunk+0x5/0x5f ? __kthread_parkme+0x82/0x140 ? __pfx_worker_thread+0x10/0x10 kthread+0x2a5/0x370 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x30/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Debugging Analysis: 1. The following ftrace log shows that the lockup CPU spends too much time iterating vmap_nodes and flushing TLB when purging vm_area structures. (Some info is trimmed). kworker: funcgraph_entry: | drain_vmap_area_work() { kworker: funcgraph_entry: | mutex_lock() { kworker: funcgraph_entry: 1.092 us | __cond_resched(); kworker: funcgraph_exit: 3.306 us | } ... ... kworker: funcgraph_entry: | flush_tlb_kernel_range() { ... ... kworker: funcgraph_exit: # 7533.649 us | } ... ... kworker: funcgraph_entry: 2.344 us | mutex_unlock(); kworker: funcgraph_exit: $ 23871554 us | } The drain_vmap_area_work() spends over 23 seconds. There are 2805 flush_tlb_kernel_range() calls in the ftrace log. * One is called in __purge_vmap_area_lazy(). * Others are called by purge_vmap_node->kasan_release_vmalloc. purge_vmap_node() iteratively releases kasan vmalloc allocations and flushes TLB for each vmap_area. - [Rough calculation] Each flush_tlb_kernel_range() runs about 7.5ms. -- 2804 * 7.5ms = 21.03 seconds. -- That's why a soft lock is triggered. 2. Extending the soft lockup time can work around the issue (For example, # echo ---truncated---
How severe is CVE-2024-56559?
CVE-2024-56559 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2024-56559 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-56559?
CVE-2024-56559 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-56559?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-56559 have an EU (EUVD) identifier?
Yes. CVE-2024-56559 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-53207.
When was CVE-2024-56559 published?
CVE-2024-56559 was published on 2024-12-27 and last updated on 2026-06-17.

References

Affected products (1)

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